Nuclear power workers will next week join a growing wave of industrial unrest that yesterday saw more than 3,000 oil and gas workers walk out in protest at against construction jobs going to foreign workers.

As demonstrations spread from Lincolnshire to Scotland, Wales and Northern Ireland, many of the protesters targeted their anger on Gordon Brown over his pledge to deliver "British jobs for British workers."

The wildcat action began on Thursday when hundreds of workers gathered at Total's Lindsey oil refinery in Lincolnshire to protest against the company's decision to award a £200m construction contract to an Italian firm, IREM, which plans to carry out the work using Italian and Portuguese staff.

The contract is one of several major construction jobs in the energy industry to go to a foreign contractor, but with UK unemployment rising fast, unions say workers are increasingly angry about what they feel are unfair practices by employers. As well as Lindsey, trade unions and companies reported that workers at least 12 other sites including refineries, power plants, gas terminals and chemical plants staged demonstrations on Friday.

More than 1,500 workers staged unofficial walkouts at six sites in Scotland in support of the dispute. There were also demonstrations at the Wilton refinery on Teeside, the Milford Haven natural gas terminal, Pembrokeshire, and the South Wales Kilroot Power station in County Antrim.More workers could walk out next week in sympathy, including hundreds of contractors at Sellafield, the country's biggest nuclear power plant.

A BNFL, which owns the Cumbrian nuclear plant, confirmed that 900 contractors at Sellafield plan to meet before work on Monday to discuss taking industrial action in support of Lindsey workers. The firms said it was confident a walkout "would have no impact on safety, security or production." Unite, the country's biggest union, on Friday called for workers from across the UK to converge on Westminster in a "national protest" to put pressure on Mr Brown over labour laws.

It also said it was consulting lawyers over claims -- disputed by the firms -- that contractors may have acted unlawfully by failing to allow UK workers to compete for jobs on UK projects.Derek Simpson, Unite's joint leader, said: "The union is doing everything in its power to ensure that employers end this immoral, potentially illegal and politically dangerous practice of excluding UK workers from some construction projects."

Since becoming Prime Minister in 2007, Mr Brown has several times used his "British jobs for British workers" slogan.Critics point out that European Union laws allowing EU nationals to work freely in Britain make the phrase meaningless and some Labour MPs have accused Mr Brown of pandering to xenophobia. Godfrey Bloom, UK Independence Party MEP whose Yorkshire and the Humber constituency covers the Lindsey plant, said Mr Brown's words are now coming back to haunt him